1. Field of the Invention
The present invention relates to the field of semiconductor wafer processing, and more particularly, to an integrated processing system for use with non-compatible processing steps.
2. Related Applications
The present invention is related to the U.S. patent application entitled "Process Chamber and Method for Depositing and/or Removing Material on a Substrate," Ser. No. 08/916,564, filed Aug. 22, 1997, and the U.S. patent application entitled "Multiple Station Processing Chamber and Method for Depositing and/or Removing Material on a Substrate", Ser. No. 09/118,664, filed Jul. 17, 1998, each of which is incorporated herein by reference.
3. Description of the Related Art
In order to fabricate features, circuits, and devices on a substrate, such as a semiconductor wafer, various techniques may be used to deposit and etch materials on the substrate. Deposition techniques include processes such as physical vapor deposition (PVD), chemical vapor deposition (CVD), sputtering, and electrochemical deposition by immersing the substrate in an electrolyte solution. This last technique applies to both electroless deposition and electroplating.
Similarly, a number of techniques are known for removing a material from a wafer. These techniques include reactive ion etching (RIE), plasma etching, chemical-mechanical polishing (CMP), and immersion of the wafer in an electrolyte solution. Material removal by subjecting a wafer to an electrolyte is often referred to as electropolishing since in this instance charged particles are removed rather than deposited on the wafer.
Various processing chambers have been used in which a substrate, such as a semiconductor wafer, is exposed to one of the above processing steps. The processing chamber used to deposit and/or remove material on a wafer may be sealed to allow the process to occur in a vacuum or positive pressure. The process may also be performed at ambient pressure.
Processing chambers have been designed in which multiple processing stations or modules are arranged in a cluster to form a cluster tool. The cluster tools or systems are often used to process a multiple number of wafers at the same time. Generally, cluster tools are configured with multiple processing stations or modules. Radial cluster tools place these in a radial arrangement around a central handling mechanism and are designed to perform a certain type of processing operation. For example, plasma etching may be performed by a clustered etcher so that multiple wafers can be etched at the same time. The use of cluster tools to process semiconductor wafers, as well as the loading and unloading of wafers (or a cassette of wafers) is known in the art.
Since many processing steps are not compatible with one another, cluster tools are designed for a specific operation. For example, sputtering or CVD processing steps both typically require a vacuum environment, while the deposition plating processes can be performed at ambient pressure. For this reason, known cluster tools are generally designed to operate having a particular environmental condition. For a wafer to be processed within a different environment, it must be moved to another station or system. This requires a complete sequence of unloading, transporting, and reloading of the wafers.
The present invention describes a technique that allows the isolation of noncompatible processes used in semiconductor manufacturing, but in which processes requiring different environmental conditions can be made to operate together. The present invention describes an integrated processing system having processing chambers or modules coupled together to allow a wafer to be moved from one isolated processing chamber or module to another isolated processing chamber or module within a controlled environment. The present invention allows both multiple station processing chambers and cluster tools to be coupled together via a connecting interface to effect the transfer.